Is there a pathogenetic role of hepatitis B virus in lupus nephritis?

In view of the widely disputed frequency with which hepatitis B surface antigen (HBsAg) is found in the sera and kidney biopsy specimens of patients with systemic lupus erythematosus (SLE), serologic screening of HBsAg and immunofluorescence studies for HBsAg and hepatitis B core antigen in renal biopsy specimens were performed in 45 patients with SLE. Five of the 45 patients with SLE had HBs antigenemia, and the prevalence was not significantly different from that of the general population in Hong Kong. The renal biopsy findings of these five patients showed lupus nephritis in two and features suggestive of hepatitis-induced glomerulonephritis in three. Our findings do not support an increased prevalence of HBsAg in sera or kidney of patients with SLE, and hepatitis B virus is unlikely to have a pathogenetic role in SLE in areas where both SLE and HBs antigenemia are common.